Phone battery drain rate calculator
Calculate percentage points used per hour and a simple 100-to-0 runtime projection.
Calculate percentage points used per hour and a simple 100-to-0 runtime projection.
Estimated result
Use the calculator
Enter start percent, end percent, elapsed hours. The calculation runs locally in this browser and returns drain rate and projected runtime.
Read the estimate carefully
Use the result as a comparison point for similar sessions, not as a hidden sensor reading or a hardware diagnosis.
- The projection assumes the same load continues.
- Short samples and background tasks can distort the result.